An international team of researchers have found traces of several metals in one of the least dense exoplanets ever discovered. A team from Cambridge University and the Institute of Astrophysics of Canada (IAC) in Spain used the Large Canary Telescope to observe WASP-127b, a giant gas planet with partially clear skies and traces of metals in the atmosphere.
WASP-127b has a radius 1.4 times that of Jupiter, but only 20% of its mass. It is located 332 light years from the Sun. Such a planet has no analogues in the solar system and is rarely found even in the thousands of exoplanets discovered to date. It takes about four days to orbit the parent star, and its surface temperature is about 1127 ° C.
Observations of WASP-127b show the presence of a high concentration of alkali metals in its atmosphere, which makes it possible to simultaneously detect sodium, potassium and lithium in the composition of the exoplanet itself. The absorption of sodium and potassium is very high, which is typical for relatively clean atmospheres. According to the modeling work carried out by the researchers, the sky of WASP-127b is approximately 50%.
"The special characteristics of this planet allowed us to study in detail its rich atmospheric composition," said Dr. Go Chen, an IAC researcher and first author of the study. "The presence of lithium is important for understanding the evolutionary history of the planetary system and may shed light on how the planet was formed."
The researchers also found possible signs of water. "While this detection is not statistically significant because water is weak in the visible range, our data indicate that additional near infrared observations should be able to detect it," said study co-author Enric Palle.
The results demonstrate the potential of ground-based telescopes for studying planetary atmospheres. “The discovery of a trace element such as lithium in the planetary atmosphere is a major breakthrough and motivates new observations and detailed theoretical simulations to confirm the findings,” said Dr Nikku Madhusudhan of the Cambridge Institute of Astronomy.
We are just starting to study exoplanet atmospheres with ground-based telescopes, but the authors believe that WASP-127b will be a reference exoplanet for future exploration using the James Webb Telescope, the successor to the Hubble Telescope.